SWL is the safe working load at the crane hook. It is also known as: rating, rated load or lift capacity. Radius is the reach, or distance from the center of rotation (center of crane pedestal) to the crane hook/center of gravity of the cargo. A higher radius will produce a larger tipping moment and cause the crane to topple if the SWL is not reduced. Even though pedestal cranes do not topple, the concept is the same.
Which is bigger, a 40 ton crane or a 100 ton crane? This is a misleading question since there is not enough information provided. SWL @ its RADIUS must be provided. A crane that can lift only 40 tons at a radius of 50 ft is twice as big as a crane that can lift 100 tons but at a radius of only10ft (40 x 50 = 2000 ton-ft, 100 x 10 = 1000 ton-ft tipping moment). So be careful and always specify the SWL @ RADIUS.
Note that whereas SWL is the safe working load at (below) the crane hook, SWLH is SWL + the weight of the hook block. SWLH is the load that the crane is subject to (if no motions are present or load factors applied) since, naturally, the crane lifts the SWL and the hook block.